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The invention relates to a reactor comprising two reaction zones and processes for the production of alkenes from alkanes. A first reaction zone includes a combustion catalyst, and a second reaction zone comprises a heating zone in thermal contact with the first reaction zone. One process comprises

The invention relates to a reactor comprising two reaction zones and processes for the production of alkenes from alkanes. A first reaction zone includes a combustion catalyst, and a second reaction zone comprises a heating zone in thermal contact with the first reaction zone. One process comprises generating heat and an effluent by the combustion of a fuel with oxygen in the first reaction zone; passing an alkane feed through the heating zone of the second reaction zone such that the alkane feed absorbs a sufficient amount of the heat generated in the first reaction zone to initiate the conversion of alkanes to alkenes in the second reaction zone. In other embodiments, the effluent comprises oxygen, and the second reaction zone excludes a catalyst; alternatively, the effluent is substantially free of oxygen, and the second reaction zone comprises a supplemental oxygen feed and may or may not include a catalyst.

대표청구항 ▼

What is claimed is: 1. A process for the production of alkenes from alkanes, comprising: (A) feeding a first zone feed to a first reaction zone having a combustion catalyst, wherein the first zone feed comprises an oxygen-containing gas and a fuel; (B) contacting the first zone feed with the combus

What is claimed is: 1. A process for the production of alkenes from alkanes, comprising: (A) feeding a first zone feed to a first reaction zone having a combustion catalyst, wherein the first zone feed comprises an oxygen-containing gas and a fuel; (B) contacting the first zone feed with the combustion catalyst under conditions sufficient to combust at least a portion of the fuel so as to form a first reaction zone effluent having less than about 1,000 ppm oxygen; (C) feeding the first reaction zone effluent to a second reaction zone; (D) introducing an oxygen-containing feed and an alkane feed to the second reaction zone; and (E) reacting at least a portion of the alkane feed with oxygen in the second reaction zone at conditions sufficient to form an alkene product. 2. The process of claim 1, wherein the fuel comprises hydrogen, carbon monoxide, C1-C4 alkanes, C1-C4 alkenes, naphtha, natural gas, syngas, or mixtures thereof. 3. The process of claim 2, wherein the first zone feed has a molar O2:C ratio less than 2:1. 4. The process of claim 1, wherein the fuel comprises carbon monoxide. 5. The process of claim 4, wherein the first zone feed has a molar O2:C ratio less than 1:2. 6. The process of claim 1, wherein step (A) further comprises preheating the first zone feed prior to feeding the first zone feed to the first reaction zone. 7. The process of claim 1, wherein the conditions sufficient of step (B) include temperatures of from about 200째 C. to about 1,000째 C. 8. The process of claim 1, wherein the combustion catalyst comprises platinum, palladium, rhodium, ruthenium, iridium, osmium, chromium, or combinations thereof. 9. The process of claim 1, wherein the combustion catalyst comprises platinum, palladium, chromium, or combinations thereof. 10. The process of claim 1, wherein the first reaction zone comprises a diluted catalytic bed comprising the combustion catalyst and a diluent material. 11. The process of claim 10, wherein the diluent material comprises a refractory oxide. 12. The process of claim 1, wherein the first reaction zone effluent comprises less than 100 ppm oxygen. 13. The process of claim 1, wherein the second reaction zone comprises an inorganic oxide. 14. The process of claim 1, wherein the second reaction zone excludes a catalyst. 15. The process of claim 1, wherein the second reaction zone includes a catalyst comprising a metal from the group consisting of Groups 2, 4-7, 11-15 metals of the Periodic Table of the Elements, scandium, yttrium, actnium, iron, cobalt, nickel, oxides of any such metals, and combinations thereof. 16. The process of claim 1, wherein the alkane feed and the oxygen-containing feed are mixed prior to being introduced in step (D) to the second reaction zone. 17. The process of claim 1, wherein the alkane feed comprises ethane. 18. The process of claim 1, wherein the alkane feed further comprises oxygen. 19. The process of claim 18, wherein the alkane feed comprises an alkane to oxygen molar ratio of from about 1.6:1 to about 10:1. 20. The process of claim 1, wherein the conditions sufficient of step (E) include temperatures from about 600째 C. to about 1,200째 C. 21. The process of claim 1, wherein the process comprises an alkane conversion of at least about 60 percent, and an alkene selectivity of at least about 50 percent. 22. The process of claim 1, wherein the second reaction zone comprises a heating zone in thermal contact with the first reaction zone, and wherein step (D) further comprises heating the alkane feed through the heating zone by heat transfer from the first reaction zone to the heating zone. 23. The process of claim 22, wherein the alkane feed and the oxygen-containing feed are introduced separately, and the oxygen-containing feed is introduced to the second reaction zone without passing through the heating zone. 24. A process for the production of alkenes from alkanes, comprising: (A) feeding a first zone feed to a first reaction zone having a combustion catalyst, wherein the first zone feed comprises an oxygen-containing gas and a fuel; (B) contacting the first zone feed with the combustion catalyst under conditions sufficient to combust at least a portion of the fuel so as to produce heat and a combustion zone effluent; (C) feeding an alkane feed to a second reaction zone comprising a heating zone, wherein the heating zone is in thermal contact with the first reaction zone through a dividing element that allows at least a fraction of the heat produced in the first reaction zone to be transferred to the heating zone, and wherein the dividing element does not allow permeation of gaseous components to and from the heating zone and the first reaction zone, and further wherein the alkane feed passes through the heating zone and absorbs a sufficient amount of the heat produced in the first reaction zone to initiate the conversion of at least one alkane to an alkene in the second reaction zone; and (D) converting at least a portion of the alkane feed so as to form an alkene product. 25. The process of claim 24, wherein the fuel comprises hydrogen, carbon monoxide, C1-C4 alkanes, C1-C4 alkenes, naphtha, natural gas, syngas, or mixtures thereof. 26. The process of claim 24, wherein the alkane feed comprises ethane, and wherein the alkene product comprises ethylene. 27. The process of claim 24, wherein the alkane feed further comprises an oxygen-containing gas. 28. The process of claim 27, wherein the alkane feed comprises an alkane to oxygen molar ratio of from about 1.6:1 to about 10:1. 29. A process for the production of alkenes from alkanes, comprising: (A) feeding a first zone feed to a first reaction zone having a combustion catalyst, wherein the first zone feed comprises an oxygen-containing gas and a fuel; (B) contacting the first zone feed with the combustion catalyst under conditions sufficient to combust at least a portion of the fuel so as to form a first reaction zone effluent; (C) providing an alkene production zone comprising a heating zone in thermal contact with the first reaction zone through a dividing element that allows at least a fraction of the heat produced in the first reaction zone to be transferred to the heating zone and wherein the dividing element does not allow permeation of gaseous components to and from the heating zone and the first reaction zone, and further wherein the alkene production zone excludes a catalyst; (D) passing the first reaction zone effluent to the alkene production zone; (E) introducing an alkane feed to the alkene production zone; (F) heating the alkane feed through the heating zone of the alkene production zone by heat transfer from the first reaction zone to the heating zone; and (G) reacting at least a portion of the alkane feed with oxygen in the alkene production zone at conditions sufficient to form an alkene product. 30. The process of claim 29, wherein the fuel comprises hydrogen, carbon monoxide, C1-C4 alkanes, C1-C4 alkenes, naphtha, natural gas, syngas, or mixtures thereof. 31. The process of claim 30, wherein the first zone feed has a molar O2:C ratio less than 2:1. 32. The process of claim 29, wherein the fuel comprises carbon monoxide. 33. The process of claim 32, wherein the first zone feed has a molar O2:C ratio less than 1:2. 34. The process of claim 29, wherein step (A) further comprises preheating the first zone feed prior to feeding the first zone feed to the first reaction zone. 35. The process of claim 29, wherein the conditions sufficient of step (B) include temperatures of from about 200째 C. to about 1,000째 C. 36. The process of claim 29, wherein the combustion catalyst comprises platinum, palladium, chromium, or combinations thereof. 37. The process of claim 29, wherein the first reaction zone comprises a diluted catalytic bed comprising the combustion catalyst and a diluent material. 38. The process of claim 37, wherein the diluent material comprises a refractory oxide. 39. The process of claim 37, wherein the diluted catalytic bed comprises a diluent material-to-catalyst weight ratio between about 1:2 and about 10:1. 40. The process of claim 29, wherein the alkene production zone comprises an inorganic oxide. 41. The process of claim 29, wherein the alkane feed comprises ethane, and the alkene product comprises ethylene. 42. The process of claim 29, wherein the alkane feed further comprises oxygen. 43. The process of claim 42, wherein the alkane feed comprises an alkane to oxygen molar ratio of from about 1.6:1 to about 10:1. 44. The process of claim 29, wherein the conditions sufficient of step (G) include temperatures from about 600째 C. to about 1, 200째 C. 45. The process of claim 29, wherein the process comprises an alkane conversion of at least about 60 percent, and an alkene selectivity of at least about 50 percent. 46. The process of claim 29, further comprising introducing a supplemental oxygen feed to the alkene production zone without passing it through the heating zone. 47. The process of claim 29, wherein the first reaction zone effluent contains at least 1000 ppm oxygen. 48. The process of claim 24, wherein the second reaction zone includes a catalyst. 49. The process of claim 24, wherein the combustion zone effluent comprises less than about 1,000 ppm oxygen. 50. The process of claim 49, wherein the alkane feed further comprises an oxygen-containing gas. 51. The process of claim 24, wherein the alkane feed flows through the heating zone in the same direction as the gaseous components in the first reaction zone. 52. The process of claim 24, wherein the alkane feed is fed at ambient temperature to the second reaction zone. 53. The process of claim 24, wherein the alkene product exits the heating zone of the second reaction zone and mixes with the combustion zone effluent to form a mixed product stream. 54. The process of claim 53, wherein the mixed product stream is fed to an alkene production catalyst bed. 55. The process of claim 54, wherein a supplemental oxygen stream is further fed to the alkene production catalyst bed. 56. A process for the production of alkenes from alkanes, comprising: (A) feeding a first zone feed to a first reaction zone having a syngas catalyst, wherein the first zone feed comprises an oxygen-containing gas and a fuel; (B) contacting the first zone feed with the syngas catalyst under conditions sufficient to react at least a portion of the fuel with oxygen so as to produce heat and a first zone effluent comprising carbon monoxide, optionally carbon dioxide, and hydrogen; (C) feeding an alkane feed to a second reaction zone comprising a heating zone, wherein the heating zone is in thermal contact with the first reaction zone through a dividing element that allows at least a fraction of the heat produced in the first reaction zone to be transferred to the heating zone, and wherein the dividing element does not allow permeation of gaseous components to and from the heating zone and said first reaction zone, and wherein the alkane feed passes through the heating zone and absorbs a sufficient amount of the heat produced in the first reaction zone to initiate the conversion of at least one alkane to an alkene in the second reaction zone; and (D) converting at least a portion of the alkane feed so as to form an alkene product. 57. The process of claim 56, further comprising feeding the first zone effluent to the second reaction zone. 58. The process of claim 56, wherein the first zone effluent comprises at least about 1,000 ppm oxygen. 59. The process of claim 56, wherein the first zone effluent comprises less than about 1,000 ppm oxygen. 60. The process of claim 56, wherein the alkane feed further comprises oxygen. 61. The process of claim 60, wherein the alkane feed comprises an alkane to oxygen molar ratio of from about 1.6:1 to about 10:1. 62. The process of claim 56, wherein the alkene product exits the heating zone of the second reaction zone and mixes with the first zone effluent to form a mixed product stream. 63. The process of claim 62, wherein the mixed product stream is fed to an alkene production catalyst bed. 64. The process of claim 63, wherein a supplemental oxygen stream is further fed to the alkene production catalyst bed. 65. The process of claim 56, wherein the fuel comprises hydrogen, carbon monoxide, C1-C4 alkanes, C1-C4 alkenes, naphtha, natural gas, syngas, or mixtures thereof. 66. The process of claim 24, wherein the alkane feed further comprises steam. 67. The process of claim 24, wherein the dividing element has the shape of a tube with a first surface area in contact with the first reaction zone and a second surface area in contact with the heating zone such that the first surface area and the second surface area are on opposite sides of the dividing element.